EEVEE: Render Passes

This patch adds new render passes to EEVEE. These passes include:

* Emission
* Diffuse Light
* Diffuse Color
* Glossy Light
* Glossy Color
* Environment
* Volume Scattering
* Volume Transmission
* Bloom
* Shadow

With these passes it will be possible to use EEVEE effectively for
compositing. During development we kept a close eye on how to get similar
results compared to cycles render passes there are some differences that
are related to how EEVEE works. For EEVEE we combined the passes to
`Diffuse` and `Specular`. There are no transmittance or sss passes anymore.
Cycles will be changed accordingly.

Cycles volume transmittance is added to multiple surface col passes. For
EEVEE we left the volume transmittance as a separate pass.

Known Limitations

* All materials that use alpha blending will not be rendered in the render
  passes. Other transparency modes are supported.
* More GPU memory is required to store the render passes. When rendering
  a HD image with all render passes enabled at max extra 570MB GPU memory is
  required.

Implementation Details

An overview of render passes have been described in
https://wiki.blender.org/wiki/Source/Render/EEVEE/RenderPasses

Future Developments

* In this implementation the materials are re-rendered for Diffuse/Glossy
  and Emission passes. We could use multi target rendering to improve the
  render speed.
* Other passes can be added later
* Don't render material based passes when only requesting AO or Shadow.
* Add more passes to the system. These could include Cryptomatte, AOV's, Vector,
  ObjectID, MaterialID, UV.

Reviewed By: Clément Foucault

Differential Revision: https://developer.blender.org/D6331

1 files changed, 71 insertions, 7 deletions

diff --git a/source/blender/draw/engines/eevee/eevee_private.h b/source/blender/draw/engines/eevee/eevee_private.h
index 7810de289df..db29e103226 100644
--- a/source/blender/draw/engines/eevee/eevee_private.h
+++ b/source/blender/draw/engines/eevee/eevee_private.h
@@ -141,6 +141,13 @@ extern struct DrawEngineType draw_engine_eevee_type;
 #define MIN_CUBE_LOD_LEVEL 3
 #define MAX_PLANAR_LOD_LEVEL 9
 
+/* All the renderpasses that use the GPUMaterial for accumulation */
+#define EEVEE_RENDERPASSES_MATERIAL \
+  (EEVEE_RENDER_PASS_EMIT | EEVEE_RENDER_PASS_DIFFUSE_COLOR | EEVEE_RENDER_PASS_DIFFUSE_LIGHT | \
+   EEVEE_RENDER_PASS_SPECULAR_COLOR | EEVEE_RENDER_PASS_SPECULAR_LIGHT | \
+   EEVEE_RENDER_PASS_ENVIRONMENT)
+#define MAX_MATERIAL_RENDER_PASSES 6
+#define MAX_MATERIAL_RENDER_PASSES_UBO 6
 /* World shader variations */
 enum {
   VAR_WORLD_BACKGROUND = 0,
@@ -198,6 +205,7 @@ typedef struct EEVEE_BoundBox {
 typedef struct EEVEE_PassList {
   /* Shadows */
   struct DRWPass *shadow_pass;
+  struct DRWPass *shadow_accum_pass;
 
   /* Probes */
   struct DRWPass *probe_background;
@@ -220,6 +228,7 @@ typedef struct EEVEE_PassList {
   struct DRWPass *bloom_downsample;
   struct DRWPass *bloom_upsample;
   struct DRWPass *bloom_resolve;
+  struct DRWPass *bloom_accum_ps;
   struct DRWPass *dof_down;
   struct DRWPass *dof_scatter;
   struct DRWPass *dof_resolve;
@@ -228,11 +237,11 @@ typedef struct EEVEE_PassList {
   struct DRWPass *volumetric_scatter_ps;
   struct DRWPass *volumetric_integration_ps;
   struct DRWPass *volumetric_resolve_ps;
+  struct DRWPass *volumetric_accum_ps;
   struct DRWPass *ssr_raytrace;
   struct DRWPass *ssr_resolve;
   struct DRWPass *sss_blur_ps;
   struct DRWPass *sss_resolve_ps;
-  struct DRWPass *sss_accum_ps;
   struct DRWPass *sss_translucency_ps;
   struct DRWPass *color_downsample_ps;
   struct DRWPass *color_downsample_cube_ps;
@@ -264,6 +273,7 @@ typedef struct EEVEE_PassList {
   struct DRWPass *sss_pass_cull;
   struct DRWPass *material_pass;
   struct DRWPass *material_pass_cull;
+  struct DRWPass *material_accum_pass[MAX_MATERIAL_RENDER_PASSES];
   struct DRWPass *refract_pass;
   struct DRWPass *transparent_pass;
   struct DRWPass *background_pass;
@@ -281,6 +291,9 @@ typedef struct EEVEE_FramebufferList {
   struct GPUFrameBuffer *bloom_blit_fb;
   struct GPUFrameBuffer *bloom_down_fb[MAX_BLOOM_STEP];
   struct GPUFrameBuffer *bloom_accum_fb[MAX_BLOOM_STEP - 1];
+  struct GPUFrameBuffer *bloom_pass_accum_fb;
+  struct GPUFrameBuffer *shadow_accum_fb;
+  struct GPUFrameBuffer *ssr_accum_fb;
   struct GPUFrameBuffer *sss_blur_fb;
   struct GPUFrameBuffer *sss_blit_fb;
   struct GPUFrameBuffer *sss_resolve_fb;
@@ -292,9 +305,11 @@ typedef struct EEVEE_FramebufferList {
   struct GPUFrameBuffer *volumetric_fb;
   struct GPUFrameBuffer *volumetric_scat_fb;
   struct GPUFrameBuffer *volumetric_integ_fb;
+  struct GPUFrameBuffer *volumetric_accum_fb;
   struct GPUFrameBuffer *screen_tracing_fb;
   struct GPUFrameBuffer *refract_fb;
   struct GPUFrameBuffer *mist_accum_fb;
+  struct GPUFrameBuffer *material_accum_fb;
   struct GPUFrameBuffer *renderpass_fb;
   struct GPUFrameBuffer *ao_accum_fb;
   struct GPUFrameBuffer *velocity_resolve_fb;
@@ -320,8 +335,11 @@ typedef struct EEVEE_TextureList {
   struct GPUTexture *color_post; /* R16_G16_B16 */
   struct GPUTexture *mist_accum;
   struct GPUTexture *ao_accum;
-  struct GPUTexture *sss_dir_accum;
-  struct GPUTexture *sss_col_accum;
+  struct GPUTexture *sss_accum;
+  struct GPUTexture *material_accum[MAX_MATERIAL_RENDER_PASSES];
+  struct GPUTexture *bloom_accum;
+  struct GPUTexture *ssr_accum;
+  struct GPUTexture *shadow_accum;
   struct GPUTexture *refract_color;
   struct GPUTexture *taa_history;
 
@@ -333,6 +351,8 @@ typedef struct EEVEE_TextureList {
   struct GPUTexture *volume_transmit;
   struct GPUTexture *volume_scatter_history;
   struct GPUTexture *volume_transmit_history;
+  struct GPUTexture *volume_scatter_accum;
+  struct GPUTexture *volume_transmittance_accum;
 
   struct GPUTexture *lookdev_grid_tx;
   struct GPUTexture *lookdev_cube_tx;
@@ -361,6 +381,17 @@ typedef struct EEVEE_StorageList {
   LightCacheTexture *lookdev_cube_mips;
 } EEVEE_StorageList;
 
+/* ************ RENDERPASS UBO ************* */
+typedef struct EEVEE_RenderPassData {
+  int renderPassDiffuse;
+  int renderPassDiffuseLight;
+  int renderPassGlossy;
+  int renderPassGlossyLight;
+  int renderPassEmit;
+  int renderPassSSSColor;
+  int _pad[2];
+} EEVEE_RenderPassData;
+
 /* ************ LIGHT UBO ************* */
 typedef struct EEVEE_Light {
   float position[3], invsqrdist;
@@ -408,6 +439,7 @@ BLI_STATIC_ASSERT_ALIGN(EEVEE_Light, 16)
 BLI_STATIC_ASSERT_ALIGN(EEVEE_Shadow, 16)
 BLI_STATIC_ASSERT_ALIGN(EEVEE_ShadowCube, 16)
 BLI_STATIC_ASSERT_ALIGN(EEVEE_ShadowCascade, 16)
+BLI_STATIC_ASSERT_ALIGN(EEVEE_RenderPassData, 16)
 
 BLI_STATIC_ASSERT(sizeof(EEVEE_Shadow) * MAX_SHADOW +
                           sizeof(EEVEE_ShadowCascade) * MAX_SHADOW_CASCADE +
@@ -708,6 +740,10 @@ typedef struct EEVEE_ViewLayerData {
   struct GPUUniformBuffer *grid_ubo;
   struct GPUUniformBuffer *planar_ubo;
 
+  /* Material Render passes */
+  struct EEVEE_RenderPassData renderpass_data[MAX_MATERIAL_RENDER_PASSES_UBO];
+  struct GPUUniformBuffer *renderpass_ubo[MAX_MATERIAL_RENDER_PASSES_UBO];
+
   /* Common Uniform Buffer */
   struct EEVEE_CommonUniformBuffer common_data;
   struct GPUUniformBuffer *common_ubo;
@@ -759,6 +795,7 @@ typedef struct EEVEE_Data {
 
 typedef struct EEVEE_PrivateData {
   struct DRWShadingGroup *shadow_shgrp;
+  struct DRWShadingGroup *shadow_accum_shgrp;
   struct DRWShadingGroup *depth_shgrp;
   struct DRWShadingGroup *depth_shgrp_cull;
   struct DRWShadingGroup *depth_shgrp_clip;
@@ -803,12 +840,17 @@ typedef struct EEVEE_PrivateData {
 
   /* Renderpasses */
   /* Bitmask containing the active render_passes */
-  eScenePassType render_passes;
+  eViewLayerEEVEEPassType render_passes;
   /* Uniform references that are referenced inside the `renderpass_pass`. They are updated
    * to reuse the drawing pass and the shading group. */
   int renderpass_type;
+  int renderpass_postprocess;
   int renderpass_current_sample;
   GPUTexture *renderpass_input;
+  GPUTexture *renderpass_col_input;
+  GPUTexture *renderpass_light_input;
+  /* The number of active material based render passes */
+  uint render_passes_material_count;
 
   /** For rendering shadows. */
   struct DRWView *cube_views[6];
@@ -860,11 +902,20 @@ struct GPUMaterial *EEVEE_material_mesh_depth_get(struct Scene *scene,
                                                   bool use_hashed_alpha,
                                                   bool is_shadow);
 struct GPUMaterial *EEVEE_material_hair_get(struct Scene *scene, Material *ma);
+struct GPUUniformBuffer *EEVEE_material_default_render_pass_ubo_get(EEVEE_ViewLayerData *sldata);
 void EEVEE_materials_free(void);
 void EEVEE_materials_draw_opaque(EEVEE_ViewLayerData *sldata, EEVEE_PassList *psl);
 void EEVEE_update_noise(EEVEE_PassList *psl, EEVEE_FramebufferList *fbl, const double offsets[3]);
 void EEVEE_update_viewvecs(float invproj[4][4], float winmat[4][4], float (*r_viewvecs)[4]);
-
+void EEVEE_material_renderpasses_init(EEVEE_Data *vedata);
+void EEVEE_material_output_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata, uint tot_samples);
+void EEVEE_material_output_accumulate(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
+int EEVEE_material_output_pass_index_get(EEVEE_ViewLayerData *UNUSED(sldata),
+                                         EEVEE_Data *vedata,
+                                         eViewLayerEEVEEPassType renderpass_type);
+int EEVEE_material_output_color_pass_index_get(EEVEE_ViewLayerData *sldata,
+                                               EEVEE_Data *vedata,
+                                               eViewLayerEEVEEPassType renderpass_type);
 /* eevee_lights.c */
 void eevee_light_matrix_get(const EEVEE_Light *evli, float r_mat[4][4]);
 void EEVEE_lights_cache_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
@@ -896,6 +947,8 @@ void EEVEE_shadows_draw_cascades(EEVEE_ViewLayerData *sldata,
                                  EEVEE_Data *vedata,
                                  DRWView *view,
                                  int cascade_index);
+void EEVEE_shadow_output_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata, uint tot_samples);
+void EEVEE_shadow_output_accumulate(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
 void EEVEE_shadows_free(void);
 
 /* eevee_sampling.c */
@@ -995,6 +1048,8 @@ void EEVEE_depth_of_field_free(void);
 int EEVEE_bloom_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
 void EEVEE_bloom_cache_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
 void EEVEE_bloom_draw(EEVEE_Data *vedata);
+void EEVEE_bloom_output_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata, uint tot_samples);
+void EEVEE_bloom_output_accumulate(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
 void EEVEE_bloom_free(void);
 
 /* eevee_occlusion.c */
@@ -1016,6 +1071,11 @@ int EEVEE_screen_raytrace_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
 void EEVEE_screen_raytrace_cache_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
 void EEVEE_refraction_compute(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
 void EEVEE_reflection_compute(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
+void EEVEE_reflection_output_init(EEVEE_ViewLayerData *sldata,
+                                  EEVEE_Data *vedata,
+                                  uint tot_samples);
+void EEVEE_reflection_output_accumulate(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
+
 void EEVEE_screen_raytrace_free(void);
 
 /* eevee_subsurface.c */
@@ -1055,10 +1115,12 @@ void EEVEE_renderpasses_init(EEVEE_Data *vedata);
 void EEVEE_renderpasses_output_init(EEVEE_ViewLayerData *sldata,
                                     EEVEE_Data *vedata,
                                     uint tot_samples);
-void EEVEE_renderpasses_output_accumulate(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
+void EEVEE_renderpasses_output_accumulate(EEVEE_ViewLayerData *sldata,
+                                          EEVEE_Data *vedata,
+                                          bool post_effect);
 void EEVEE_renderpasses_postprocess(EEVEE_ViewLayerData *sldata,
                                     EEVEE_Data *vedata,
-                                    eScenePassType renderpass_type);
+                                    eViewLayerEEVEEPassType renderpass_type);
 void EEVEE_renderpasses_draw(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
 void EEVEE_renderpasses_draw_debug(EEVEE_Data *vedata);
 void EEVEE_renderpasses_free(void);
@@ -1087,6 +1149,8 @@ void EEVEE_volumes_cache_finish(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata)
 void EEVEE_volumes_draw_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
 void EEVEE_volumes_compute(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
 void EEVEE_volumes_resolve(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
+void EEVEE_volumes_output_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata, uint tot_samples);
+void EEVEE_volumes_output_accumulate(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
 void EEVEE_volumes_free_smoke_textures(void);
 void EEVEE_volumes_free(void);